With approaching of the age of big data, an electric quantity demand of a data center (for example various types of large servers) is increasingly great, and it needs to provide sufficient electrical energy for the data center. In order to deal with a case of sudden blackout of a power grid, sufficient backup electrical energy is needed, such that the data center can operate normally using the backup electrical energy even if the power grid can not supply power normally. In a power supply system of the data center, a battery and an oil engine are used to store electrical energy. In a case of designing the investment of the power supply system of the data center, the investment of a power supply system is generally considered with a priority, and no enough concern is given to model selection and configurations of the battery and the oil engine. The investment of the battery and the oil engine is great, and a cost of the power supply system will be increased if secondary investment is made due to insufficient electrical energy of the power supply system.
When the power supply system of the data center supplies power normally through the power grid, the power grid provides an alternating current to a power supply unit through an automatic transfer switch, and the power supply unit converts the alternating current into a direct current, so as to charge a later level of battery and supply power to a load to be supplied power. When the power grid blackouts, the automatic transfer switch switches to disconnect an input of the power grid from the power supply unit and connect the oil engine to the power supply unit. The oil engine provides an alternating current to the power supply unit through the automatic transfer switch, and the power supply unit converts the alternating current into a direct current to supply power to a load to be supplied power.
The conventional power supply way for the data center is described above. In a case that the oil engine and the battery are used to supply power to the load to be supplied power, generally the battery cannot be used continuously when the battery discharges in a high rate current for more than dozens of times. The life of the battery is short, and therefore the power supply time of the whole system is short, thereby resulting in poor reliability of power supply.